The primary goal of the Clinical Research Center is to conduct cross-sectional and longitudinal research of a well-defined and objectively diagnosed population of psychotic children and comparison cases. Psychotic children will receive a thorough and objective clinical evaluation aimed at providing detailed information regarding their medical, neurological, psychiatric, psychological, linguistic and auditory status. The research will focus upon a number of specific hypotheses which pertain to fundamental issues regarding the development of psychotic symptoms in infancy and childhood. Data will consist of the resuts of a series of interactive behavioral, neurobiochemical, neuroendocrinological, neuropharmacological and neurophysiological projects as well as the results of the initial clinical evaluation of each child. We believe that the development of psychotic conditions in childhood may be dependent on the interaction of both biological and experiential factors, and that for this reason research aimed at providing information necessary for the prevention and treatment of childhood psychosis must be multi-factorial in design. Additional goals of the Clinical Research Center are to provide comprehensive clinical and research training opportunities for child psychiatrists, psychologists, linguistic students, social work and nursing students, etc., and to serve as a valued didactic and clinical resource to the community at large.